Collated screws are known in which the screws are connected to each other by a retaining strip of plastic material. Such strips are taught for example by U.S. Pat. No. 4,167,229 issued Sep. 11, 1979 and related Canadian Patents 1,040,600 and 1,054,982. Screws carried by such strips are adapted to be successively incrementally advanced to a position in alignment with and to be engaged by a bit of a reciprocating, rotating power screwdriver and screwed into a workpiece. In the course of the bit engaging the screw and driving it into a workpiece, the screw becomes detached from the plastic strip leaving the strip as a continuous length.
Such screw strips are useful for being driven by a power screwdriver such as described in U.S. Pat. No. 4,146,871 issued Mar. 27, 1976.
Drywall is a well known wall covering used extensively to cover interior walls in buildings in the United States of America. Drywall is conventionally used as flat sheets of approximate dimensions of 4 ft by 8 ft (121.92 cm by 243.84 cm). Most commonly used drywall has thicknesses in the range of 1/2 inch (1.27 cm) or 5/8 inch (1.59 cm) and their metric equivalents. Conventional drywall typically comprises a gypsum core covered on each of its sides by a thin covering conventionally of a paper-like material. Drywall has many different forms providing, for example, increased strength or resistance to water. Conventional drywall can readily be cut or fractured so as to provide for ease of manual cutting the sheets to desired shapes and installation. The internal core of drywall is typically a plaster or gypsum type material which comprises a consolidated mass of material which when subjected to severe localized forces will disintegrate into a fine chalk-like powder.
In typical construction, drywall is applied over framing to form interior walls in a building. For example, conventional walls may be formed as a frame of lumber, for example, 2 inch (5.08 cm) by 6 inch (15.24 cm) wood with a top and bottom frame joined by vertical frame members typically located on 16 inch (40.64 cm) centres. A wood ceiling frame may also, for example, have horizontal stringers on 16 inch centres. After forming the framing, drywall is applied to the framing preferably by screwing the drywall sheets to the wood frame members for the walls and ceilings. For such purposes, preferably screws known as drywall screws are used which are particularly adapted for securing the drywall to the framing.
It is known to provide drywall screws as collated screws in a strip of the type taught by U.S. Pat. No. 4,167,229 and to drive such drywall screws with power screwdriver such as shown in U.S. Pat. No. 4,146,071.
The present inventor has appreciated disadvantages arising with the use of such collated drywall screws with a power driver. One disadvantage is that when driving such collated drywall screws with the power driver, and particularly when driving drywall screws vertically upwardly into a ceiling, powder from the drywall drops downwardly and with time comes to clog and jam the power driver against proper operation. Another disadvantage is that in driving screws into drywall, increased pressure needs to be applied to a power tool by a user to cause a screw to disengage the strip and pass through drywall as contrasted to driving the screws merely into wood. Applying such increased pressure is particularly disadvantage in applying screws into a ceiling or at arms length to one side.
The present inventor has appreciated that the disadvantages which arise in securing drywall with collated screws also arise in securing screws in or through other weak materials which may not have sufficient strength to draw a screw through the strip. Such other weaker materials include rigid foam insulation, insulation panels and cladding panels.